Many pathologies are presently treated with compositions of immunoglobulins (Ig). For example mention may be made of primitive immunodeficiencies with a lack of production of antibodies, Kawasaki's disease, immune thrombopenic purpura of children and adults, secondary immunodeficiencies with lack of production of antibodies, notably chronic lymphoid leukemia or a myeloma associated with recurrent infections, infection of children with the HIV associated with bacterial infections, multifocal motor neuropathies, Guillain-Barre's syndrome, severe or chronic acute infections with Parvovirus B19, acquired or constitutive immunodeficiency, cortico-resistant dermatomyositis, acute myasthenia, idiopathic chronic polyradiculoneuritis, immune thrombopenic purpura, for example associated with HIV infection, Stiffman syndrome, auto-immune neutropenia, resistant auto-immune erythroblastopenia, anti-coagulation syndrome acquired by auto-antibodies, rheumatoid polyarthritis, uveitises, etc.
The increasing use of human plasma fractions enriched in Ig in therapy requires large scale production, for example from human plasmas, of highly purified Ig concentrates, injectable via an intravenous route (IgIV), or sub-cutaneous route (Igsc).
Now this production is confronted with many constraints, notably in terms of innocuousness of the obtained Ig concentrates.
According to European Pharmacopeia, in order to reduce the risks of hemolysis, these concentrates should have a reduced content of antibodies directed against the antigens of the blood group A and/or of the blood group B (designated in the description in an abbreviated way, as “anti-blood group A antibody” and “anti-blood group B”, or further “anti-A antibody” and “anti-B antibody”, or further “anti-A isoagglutinins” and “anti-B isoagglutinins”).
Given that the needs in Ig are constantly increasing, it is necessary to have increasingly large pools of donors, which will be statistically richer in blood group O. Therefore it has become essential to have processes giving the possibility of removing the anti-A and anti-B antibodies of blood products, during the industrial production of Ig concentrates from pools of blood plasmas.
Application WO2007/077365 describes a process for preparing Ig concentrates, comprising an immunoaffinity chromatography step aiming at depleting the latter in anti-A and anti-B antibodies.